Bitcoin and companies tied to cryptocurrencies extended a nearly two-month swoon Monday, tracking with a broader market sell-off in technology companies that many see as overvalued. Bitcoin, which soared to a record $126,210.50 on Oct. 6 according to crypto trading platform Coinbase, slid 11.8% to below $85,000. Stocks across the crypto industry tumbled, with Coinbase Global sinking 5.1% and online trading platform Robinhood Markets losing 5.2%.